Precise yield of high-energy photons from Higgsino dark matter annihilation

The impact of electroweak Sudakov logarithms on the endpoint of the photon spectrum for wino dark matter annihilation was studied intensively over the last several years. In this work, we extend these results to Higgsino dark matter χ10. We achieve NLL′ resummation accuracy for narrow and intermediate spectral energy resolutions, of order mW2/mχ and m_W, respectively. This is the most accurate prediction to date for the yield of high-energy γ-rays from χ10χ10→ γ + X annihilation for the energy resolutions realized by current and next-generation telescopes. We also discuss for the first time the effect of power corrections in m_W/m_χ in this context and argue why they are not sizeable.